The Department of Biochemistry of the University of California, Berkeley, has established a Mutagenesis Center under sponsorship of the National Institute of Environmental Health Sciences. This Center unifies the efforts of a number of research groups in the Department working on various aspects of mutagenesis. A growing awareness that damage to the integrity of nucleic acids by environmental mutagens is a major problem in public health has directed many members of the Department towards more practical applications of their basic research. Nine of 18 faculty members participate in the Center. The Mutagenesis Center's main focus is on the following research areas: 1. The detection and characterization of environmental mutagens and carcinogens. 2. The study of mechanisms of mutagenesis. 3. The study of the role of genetic damage in human disease, aging and evolution. 4. The study of DNA repair and other enzymic defenses against DNA damage. 5. The study of basic mechanisms of the dynamic genetic apparatus and chromosomes in higher organisms as related to genetic stability and toxic agent action.